<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>边框属性 演示文档</title>
    <style type="text/css">
      #containner {
        position: relative;
        background-color: gray;
        width: 300px;
        height: 200px;
        border-width: 10px;

        border-style: solid;
        border-color: red;
        border-radius: 10px;
      }
    </style>
  </head>
  <body>
    <div id="containner">
      <div
        style="
          width: 100px;
          height: 100px;
          background-color: yellow;
          border: 3px solid blue;
          border-radius: 50%;
          margin: 50px auto;
        "
      >
        <p>内部div</p>
      </div>
    </div>
  </body>
</html>
